Competition of density waves and superconductivity in moiré transition metal dichalcogenide bilayers from functional renormalization

Experimental demonstrations of tunable correlation effects in magic-angle twisted bilayer graphene have put two-dimensional moiré quantum materials at the forefront of condensed-matter research. Bilayers of transition metal dichalcogenides (TMDs) have further enriched the opportunities for analysis and utilization of correlations in such systems. Recently, within the latter material class, the relevance of many-body interactions with an extended range has been demonstrated. Moiré bilayer TMDs can be accurately modelled by effective extended Hubbard models on the triangular superlattice, which define a starting point for quantum many-body approaches. In my talk, I will present a functional renormalization group approach for correlated fermion systems as a suitable quantum many-body method to describe competing Fermi surface instabilities and resulting correlated phases of moiré TMD bilayers. The concrete examples will be MoS₂/WSe₂ and twisted bilayer WSe₂. The results from this approach suggest that bilayer TMDs are unique platforms to realize topological superconductivity with high winding number which reflects in pronounced experimental signatures such as enhanced quantum Hall features and pair-density-wave superconductors.